창세기 5:28 해설: Rashi, Chizkuni, Da'at Zekenim & Siftei Chakhamim

ויולד בן AND HE BEGOT A SON (בן “son”, connected with the root בנה ‘‘to build”) — from whom the world was built up (peopled) (Tanchuma 1:1:11)

ויולד בן, “he begat a son;” the Torah did not write: “he sired Noach,” as it did in similar situations, i.e. Genesis 5,6; 5,9; Judges 11,1; Chronicles I 1,34, et al. The reason is that Noach warranted an extra verse seeing that the whole human race today exists thanks to him. The entire human race was destroyed during his lifetime; only he, his wife and his children and their wives, having been saved. A different interpretation: Metushelach, Lemech’s father, advised his son not to immediately name him as his contemporaries who were worshipping all kinds of idols, and who would curse and kill people who were monotheists, would try and kill him by telling their idols his name. After Noach had married and had sired a son, his father turned to his father again and was told then to call him Noach, as he had the potential to save all of mankind if they would follow his lifestyle. If not, they would all perish before they could harm him. (Compare Torah sh’leymah item 71 on this verse)

ויולד בן, “he begot a son.” Note that the Torah did not write “he begot Noach,” as it had done when listing the nine generations previous to Noach. This is already a hint that the future of mankind would be descended from this son of Lemech after the deluge. Noach and his three sons and their wives were the only survivors of the deluge. An alternate interpretation. Metushelach, Noach’s grandfather, a G–d fearing person, advised his son Lemech not to name his firstborn son immediately after he was born, as all the other people of that time were idolaters and sorcerers, and if they had known why his father had called him Noach they would have tried to harm him had they known his name, by applying their sorcerers’ formulas.